What is wrong with his questions? Those developers thought it was a good idea to take their complaints about the XSS to Twitter a public forum. They obviously wanted the world to know their feelings so its totally fair to ask them if they still feel the same way and why they deleted their comments. If they have an issue with XSS development why not talk to MS instead of Twitter? Their comments were better for fanboy console wars over legitimate development concerns. It's is in all their best interests to develop the best content they can and I'm certain MS has tools and tech support to ensure games look their best. Twitter does not.
I don't what's wrong with his questions either. Who cares if should have DMed them or not? Not like they were discussing anything super private or worth DMing about. They expressed their opinions publicly, then he should be able to express his questions publicly.